* {
    margin: 0;
    padding: 0;
    list-style: none;
    text-decoration: none;
}

menu {
    margin: 35% 0 0 40%;
}

menu li {
    margin-top: 10px;
    width: 235px;
    line-height: 30px;
    position: relative;
    border: solid 4px #7a7a7a;
    border-radius: 0 16px;
    overflow: hidden;
}

menu li:hover {
    border: solid 4px #f3c258;
}

.btn{
    font-size: 20px;
    position: relative;
    width: 200px;
    background: transparent;
    border: none;
    display: inline-block;
    padding: 8px 18px;
    color: #fff;
    text-align: center;
    cursor: pointer;
    white-space: nowrap;
    font-family: '微软雅黑';
    border-radius: 2px;
    background-color: #2196f3;

}
.none{
    display: none;
}

video {
    width: 100%;
    position: absolute;
    top: 0;
    left: 0;
}